Lamp tube changing tool



Oct. 27, 1959 G. DIGHERA Er'AL' LAMP TUBE CHANGING TOOL 2 Sheets-Sheet 1 Filed Nov. 5, 1954 l I Ill Oct. 27, 1959 G. DIGHERA ETAL 2,910,320

LAMP TUBE CHANGING TOOL Filed Nov. 5, 1954 2 Sheets-Sheet 2 6501765 2/6! 50/55? E. 5E/v/vErr United States Patent LAMP TUBE CHANGING TOOL George Dighera and Ernest E. Bennett, Inglewood, Calif. Application November 5, '1954, Serial No. 467,112

7 Claims. (Cl. 294-20) This invention relates to a tool for installing and removing tubular lamps, such as the well known slimline and fluorescent types.

An object of this invention is to provide a tool for removing and installing tubular lamps in sockets of the type which have end members to hold the lamps at the ends thereof, without requiring a man to climb a ladder to reach and open the socket. This tool is more particularly intended for use in connection with those sockets wherein one of the end members is spring-loaded, and must be bent back to allow the end of the lamp tube to be installed therein.

This invention is carried out by providing a frame to which there are fixed a pair of clamps adapted to be opened and closed so as to grasp and firmly hold the lamp tube. A feature of the invention resides in pusher means for opening the socket to receive or release the lamp tube. According to this invention, the pusher means comprises a pusher rod which is mounted. to the frame in such a manner that it is movable either solely in trans- 'lation, solely in rotation, or in a combination of translation and rotation. Thus, a free pusher end of the rod can be moved relative to the axis of the lamp tube either axially alone, transversely alone, or in a combination of such movements. This gives the tool a broad flexibility in movement, and its use is therefore facilitated.

An optional feature resides in providing a springing structure on the free end of said pusher rod adapted to spring over and straddle the tube, and having guiding means thereon for positioning said springing structure relative to the socket.

The above and other features of the invention will be fully understood from the following detailed description and the accompanying drawings, of which:

Fig. l is a side elevation, partly in cutaway view of a lamp changer according to the invention;

Fig. 2 is a fragmentary cross-section taken at line 2-2 of Fig. 1;

Fig. 3 is a fragmentary cross-section taken at line 3-3 of Fig. 1;

Fig. 4 is a fragmentary cross-section taken at line 4-4 of Fig. 1;

Fig. 5 is a fragmentary cross-section taken at line 5-5 of Fig. 1;

Fig. 6 is an alternate embodiment of a springing structure for the end of the pusher rod of Fig. 1;

Fig. 7 is a fragmentary side elevation taken at line 7-7 of Fig. 6;

Fig. 8 is an end view of another embodiment of a pusher element for the end of the pusher rod of Fig. 1;

Fig. 9 is a side elevation of a safety lock for use with the invention;

Fig. 10 is a side elevation of a guide member;

Fig. 11 is an end view taken at line 11-11 of Fig. 10; and

Fig. 12 is a vertical cross-section taken at line 12-12 of Fig. 9.

A lamp changing tool 10 according to the invention has a frame 11 which may conveniently be made of a piece of sheet metal. Mounting flanges 12, 13 are formed at opposite edges of the frame, and cut-out portions 14, 15 are provided near the center of the frame. A guide slot 16 is cut in flange 13 for a purpose to be described. Additional flanges 17, 18, 19 may be formed as part of an enclosure for the mechanism of the tool.

Two curved clamping arms 20, 21 are riveted to the frame so as to have a fixed position relative thereto. Two other curved clamping arms 22, 23 are mounted to a rotatable shaft 24 which is journaled in flanges 12 and 13. Clamping arms 22 and 23 are disposed respectively opposite clamping arms 20 and 21, so that a pair of clamps are provided which are spaced from each other, and are adapted to be clamped around a tube. The clamping arms may be faced with sponge rubber covers 24a to protect the tube.

A flange 2.5 is provided on clamping arm 22 to which one end of a spring 26 is attached. The other end of the spring is affixed to the frame, and thus the spring tends to hold the clamps open to receive a tube. A lever arm 27 (Fig. 2) projects radially from the shaft 24, and passes through the upper cut-out portion 14. A flexible pulling means such as a wire 27a is pinned to the end of the arm 27, and this wire passes through the other cut-out portion 15 and into a hollow handle 28 which is attached to the frame.

A bracket 29 projects from the side of the handle 28. The handle has two, longitudinal slots 30, 31 therein, and bracket 29 straddles slot 30. A lever 32 is pinned to the bracket 29 and extends transverse to and through the slots in the handle. The wire 27a is attached to a spring 33 which is itself fixed to a medial point of the lever 32, so that pivoting the lever 32 pulls the wire to close the clamps on the frame.

The slot 31 on the side of the handle 28 opposite bracket 29 has a hook 34, see Fig. 5, so that, when the lever is drawn down to firmly grasp a tube in the clamps it may be caught and held by the hook. The maximum clamp force is limited by the spring 33 which connects the wire 27a to lever 32.

Pusher means for opening the socket to receive and release a tube comprise a pusher rod 35 which passes through slot 16. The slot 16 will be longer than the width of the pusher rod so that the rod can move transversely of the axis 36 of a lamp tube 37. Springing guide means are fixed on the pusher end of the rod by means such as rivets, and conveniently comprises a pair of flexible fingers 38, 39 which can be spaced apart to embrace a lamp tube between them.

At their free ends each of these fingers has a curved guide portion 40 and a lug 41 (Fig. 4). The curved guide portions 4-0 are spaced so as to guide the fingers on opposite sides of a socket end member 42, and the lugs 41 will then bear against a face 43 thereof.

The pusher rod is supported at a medial point by a plate 44 with a slot 45 in it. This slot is longer than the width of the pusher rod, and is aligned with guide slot 16.

A crank member 46 is pivoted to the frame at 47, and may conveniently comprise a triangular plate 48. At one corner of the plate there is provided a slot 49 through which a pin 49a projects. This pin joins the inner end of the pusher rod to the crank member, and also provides a sliding connection. It will be appreciated from the drawing that the slot 49 is tilted slightly clockwise of a radial line from pivot 47. In this Way, a more positive pushing action on the pusher rod is assured. A spring 50 interconnects the frame and the inner end of the pusher rod so as to urge the free end of the rod away from the frame, transverse to the longitudinal axis 36 of the lamp tube.

A wire 51 is pinned to a point on the crank member 3 which is not in line with the pivot and slot 49. wire passes down the hollow handle 28 to connect with one arm 52 of a crank 53. The other arm 54 of the crank serves as a grip, and the crank 53 is pivoted to abracket 55 on the handle 23.

A resilient grip 56 can be provided at the end of the hollow handle 28 for a convenient hand held. The handle may be segmented as shown so that it maybe lengthened or shortened for specific uses. A convenient means is .-a tubular insert 57 inside the hollow handle 28 which extends between two adjacent handle segments. Screws 58 or other fastening means interconnect the insert and the handle segments. Any desired number of handle segments may be used with appropriate changes in the length of the wires to the lever 32and crank 43. Such a segmented construction also aids in the assembly .of the device, particularly as regards joining the wires to the levers inside the handle.

An alternate form of guide means for the pusher rod is shown in Fig. 6. Two arms S9, 60 are pinned to a pivot 61 to the end of the pusher rod, and have the same general configuration as fingers 38 and 39. These extend on both sides of the pivot, and have a spring 62 in tension between them to pull them together.

Still another embodiment of an end member for the pusher rod is shown in Fig. 8, wherein arms 63, 64 are pinned on a pivot 65 at the end of the pusher rod. A spring 66 between them pulls the arms together.

In Fig. 9 there is shown a locking device for the clamping arm movement which prevents the lever 32 from being closed until the tube is disposed inside both sets of clamps. This device comprises a pivoted locking member 67 with a striker plate 68 atop the frame. A 'detent flange 69 projects down from one side of the striker plate, and has a hook "it! at its lower end. A pivoted joint '71 serves to mount this device with the striker plate atop the frame, and with the detent member swingable sothat the hook is movable across slot 14.

The portion of the locking device to the right of pivoted joint 71 which includes the detent flange has a greater rotational moment than the striker plate, so that unless the striker plate is forced down by some object, the hook 7d stands in the way of lever 27 and prevents it from being pulled down.

In Figs. 1!) and ll there is shown a lamp guide 72 having a U-shaped clamp '73 adapted to fit onto a socket member 74. This guide has a U-shaped rest 75 spaced from the clamp, which is joined to the clamp by a metal strip 76. This guide may conveniently be made of a single piece of sheet metal, if desired, by simply bending it to form the clamp and rest. A lamp tube 77 can be laid on the rest to guide the electrode 78 into the socket member.

It will be appreciated that slot 16 in flange 13, and slot 45 in plate 44 both provide sliding mounting joints for the pushing rod. These joints are adjacent to each other. With these joints, the pusher rod can be moved solely in translation, solely in rotation, or in any combination of translation and rotation, all in a single plane. The plane in this case is that of the paper in Fig. 1., and slots 16 and 45 both lie in this plane.

Slot 49 in crank member 46 provides a sliding driving joint. The pusher rod can be moved in translation generally transverse to the axis of the lamp, and can also rotate, both in the same single plane. However, translation in a direction generally parallel to the lamp axis is restrained by this joint, and occurs only when the crank is turned. This crank movement causes the pusher rod to move in a direction generally parallel to the axis of the lamp to open the socket.

When the free end of the pusher rod is pressed transversely to the rod, the rod can rotate independently of translational movement, inasmuch as slots 16, 45, and 49 are aligned, and the rod will simply pivot, usually in one of the slots, whose structure becomes a fulcrum.

This

The operation of this tool will now be described. To install a tube in a socket, the tube is first laid between arms 20, 22 and 21, 23 and lever 32 is pulled down to tighten the clamps on the tube. One end of the tube will project slightly beyond fingers 38, 39. The tube is thus firmly held by the clamps and will neither rotate nor slide longitudinally relative to the frame. The lever 32 may be locked in hook 34, and thereafter the hand is free of lever 32.

The tool and lamp are then raised to the socket, and the fingers 38, 39 are placed one on each side of the socket member which is not spring loaded. The guide portions 4% steer the end of the pusher rod and the lugs 41 finally bear on the socket. Then the end of the lamp tube away from the free end of the pusher rod is placed in the end. of the socket which is spring loaded. Then lever 54 is pressed. This shifts the pusher rod longitudinally relative to the tube and the tube opens the socket. The tube is then moved to a level position with both electrodes being disposed opposite the socket members and the lever 54 is released. This movement of the tube upward into both sockets, while the pusher rod holds the sockets open, is made possible by the freedom of the pusher rod to move independently in either translation or rotation. Releasing the push rod permits the socket to spring back and clamp onto the lamp tube. Lever 32 is released from hook 34, opening arms 20, 22 and 21, 23 so that the lamp tube is freed from the tool, and the tool is removed, leaving the lamp installed.

To remove the lamp, the reverse of the above operations is performed.

The pusher rod ends shown in Figs. 68 operate in the same manner as that shown in Fig. 1. The additional embodiments are shown solely for illustrating other suitable type of pusher rod ends.

Occasionally, when changing lamps on a high ceiling, the operator may accidentally engage the tube with only one of the clamps. This could result in the dropping of a tube. The locking device of Fig. 9 averts this possibility. Since the device is normally pivoted so that hook 70 stands across slot 14, the lever 27 is locked in the up position, with the clamps open. However, when a lamp tube is installed squarely between both of the clamps, the tube rests against the striker plate 68 and pivots the detent flange 69 and hook 70 out of the way. The lever 27 can then be drawn down, and the clamps fastened onto the tube. Thus with this locking device, there is no possibility that the clamps can be fastened unless the lamp tube is squarely in its proper position.

The lamp guide 72 is also a convenience for working at considerable distances from the lamp tubes. The electrodes of these lamp tubes are fairly small, and must be fitted into small holes in the sockets. To aid this positioning, the end of the tube may be laid in the rest 75, and this rest will guide the tube into the socket. This rest may conveniently be a permanent part of the lamp fixture, and will be aflixed to the spring-loaded socket end, into which the lamp is first introduced when the lamp tube is "installed.

The guide means on theend of the pusher rod facilitate both removing and installing a lamp. By its floating mounting the pusher rod is free to assume, within its structural limitations, any position relative to the clamps (and therefore the lamp tube). This enables the end of the pusher rod and the lamp tube itself, to perform their operations independently of the position of the other. This tool is thereby made flexible in use, and there is no unique lever setting, particularly of lever 54, for placing the end of the pusher rod in a unique position. Because of the sliding joints, the end of the pusher rod can be moved up and down regardless of the position of lever 54, and can also be moved horizontally regardless of the vertical position. This is a significant convenience both in installing and removing lamps.

Numerous other modifications of the pusher rod and guide member will be apparent to persons skilled in the art. For instance, in the various joints, pins riding in rails might be substituted for slots, and in some cases, elements might be exchanged. Therefore this invention is not to be limited by the embodiments shown in the drawings and described in the description, which are given by way of example and not of limitation but only in accordance with the scope of the appended claims.

We claim:

1. In a tool for changing tubular lamps in sockets, said lamps having a longitudinal axis, and said tool having a frame, clamping means mounted to said frame for grasping and holding said lamp against movement relative to the frame, and means for opening and closing said clamping means around said lamp, the improvement comprising means for opening said socket to receive or release said lamp, comprising: a pusher rod extending in the general direction of said longitudinal axis when the lamp is held in said clamping means; a mounting joint for said pusher rod comprising a member fixed to the frame and having a slot therein within which slot the pusher rod is slidably disposed, the length of said slot being greater than the Width of the pusher rod, and the width of the slot being substantially equal to the thickness of the pusher rod, whereby the pusher rod is movable either solely in translation, solely in rotation, or in a combination of translation and rotation, all in a single plane, said plane being parallel to the slot; a driving joint for said pusher rod comprising a crank member rotatably mounted to the frame and having a slot therein, a pin on the pusher rod slidably engaged in said slot; and means for turning said crank so as to move the pusher rod in a direction generally parallel to the axis of the lamp, the slot in said crank member being generally transverse to said longitudinal axis, whereby a lamp can be inserted into and held by said clamping means, the end of the pusher rod placed against the socket in opposition to the tube, the crank member turned to open said socket, the lamp inserted in said socket, the crank member turned to release the socket from the pusher rod to permit the socket to engage the lamp, and the clamping means opened to release the lamp from the tool and leave the lamp in the socket.

2. Apparatus according to claim 1 in which guide means are provided on said pusher rod for engaging said socket, said guide means comprising: a pair of arms mounted to said pusher rod which are spaced apart from each other in order to straddle the lamp, lug means on said arms adapted to bear against a surface of said socket when the pusher rod is actuated to open said socket, said arms diverging as they extend away from the lugs so that they are adapted to straddle a portion of said socket, and guide the lugs toward said surface.

3. Apparatus according to claim 2 in which there is provided a striker element tiltably mounted to said frame in a position where it is engaged and displaced by a lamp when said striker element is engaged by a lamp properly held in said clamping means, and in which. said clamping means are connected to a movable lever, and a hook element on said striker element movable in and out of the path of movement of the lever, said hook element engaging said lever and preventing its movement unless said striker element is displaced by a properly positioned lamp.

4. Apparatus according to claim 3 in which the arms of said guide means include springing means tending to pull the arms together.

5. Apparatus according to claim 3 in which springing means interconnect the pusher rod adjacent to the driving joint with the frame so as to urge the end. of the pusher rod at the driving joint away from the clamp.

6. Apparatus according to claim 1 in which said clamping means includes a pair of spaced-apart clamps secured to the upper portion of the frame and adapted to engage said lamp.

7. Apparatus according to claim 1 in which the means for opening and closing the clamping means includes a handle attached to said frame, and a lever. mounted to said handle, said handle having a locking slot, said locking slot including a hook section engageable'by the lever when the clamping means are closed on a lamp.

References Cited in the file of this patent UNITED STATES PATENTS 2,145,447 Klingon Jan. 31, 1939 2,207,477 Blackmon July 9, 1939 2,371,437 Gaynor et a1. Mar. 13, 1945 2,658,786 Ziese .v c Nov. 10, 1953 

